Atomistic Simulations of Elastic and Plastic Properties in Amorphous Silicon

TL;DR

This study uses molecular dynamics simulations to explore how different potentials affect the elastic and plastic behavior of amorphous silicon, revealing defect-site correlations and shear band formation.

Contribution

It provides a detailed analysis of potential-dependent mechanical properties and defect-site localization in amorphous silicon under shear.

Findings

Plastic events prefer specific defect sites depending on the potential used.

Non-affine displacement fields localize during plastic events.

Elementary shear bands form at higher shear strains.

Abstract

We present here potential dependent mechanical properties of amorphous silicon studied through molecular dynamics (MD) at low temperature. On average, the localization of elementary plastic events and the co-ordination defect-sites appears to be correlated. For Tersoff potential and SW potential the plastic events centered on defects-sites prefer 5-fold defect sites, while for modified Stillinger-Weber potential such plastic events choose 3-fold defect sites. We also analyze the non-affine displacement field in amorphous silicon obtained for different shear regime. The non-affine displacement field localizes when plastic events occur and shows elementary shear band formation at higher shear strains.